Local Anesthetic

Sedation & Anesthesia in Dental Practice

LOCAL ANESTHESIA:

“30+ Years of Hits, Misses and Near MiSs-

THE NATIONAL NETWORK for ORAL HEALTH ACCESS es” THE 2015 ANNUAL CONFERENCE Indianapolis, Indiana November 16th , 2015

Mel Hawkins, DDS, BScD AN Dentist / Dentist Anesthesiologist Toronto, ON Canada www.sedationdentistry.us [email protected] AGENDA

1 2 3

Anatomy, What can What’s new? Blocks, go wrong Paresthesia, Road and what reversing, Blocks, to do buffering, inhalational More about it? and more Blocks PART



ANATOMY, BLOCKS, ROAD BLOCKS AND MORE BLOCKS

THE ELUSIVE McDibular BLOCK …millions and millions served . . .

Trivia: The dental local anesthesia industry combined now serves up 330 million cartridges every year in North America A=86%

B=7%

C=7%

Inferior Alveolar

Block

“Conventional” as opposed to a “mandibular block” Relationship of:

Conventional (inferior alveolar)

Akinosi, closed mouth

Gow-Gates “condylar neck”

Hybrid, “mix and match” blocks Reasons for Failure

Anatomical Variations:

• Hard tissue anatomy • Connective tissue and Neurovascular anatomy

Dr. George Gow-Gates, Dr. J. Watson, University of Sydney, Australia 3 Major Factors:

•Internal Oblique Ridge •Sphenomandibular fascial barrier •Risks: Nerves, Arteries

The distance between the internal and external oblique line of the mandible varies. Adapted from Dr. N. B. Jorgensen Netter, Grant’s Anatomy Anatomical Influences:

The maxillary artery, passes through the high pterygomandibular triangle region The Question is:

What is the risk of an intraarterial injection?

Clinically Unlikely Internal Maxillary Artery

Characteristics: • Thick smooth muscle wall • Well innervated • Constricts or arteriospasms, eliminates lumen • Artery is mobile within the anatomical area • Pulse pressure True Confessions

Histology

Horizontal X-S, level of Conventional I.A.N.Block

Courtesy Dr. G. A. E. Gow-Gates, Dr. J. Watson Horizontal X-S, level of Gow-Gates Mandibular Block

Courtesy Dr. G. A. E. Gow-Gates, Dr. J. Watson Conventional Advantages

• Intra-oral landmark for 110 years • Practitioner acceptance for 110 years • Fast onset if accurate and no neural aberrance, as in grade B and C anesthesia problems (14%)

Conventional Disadvantages

• Increased vascularity • Anatomical variance • Macroglossia • Paresthesia mechanical - lingual claims experience X2 • (Long) buccal nerve “block”

Syndrome:

“The Chin on the Chest”

Open the Airway

Coronoid Notch

Definition: Greatest antero-postero indentation depth on the anterior border of the ramus

Bevel Orientation – faces mid-sagittal plane… this way

…but deflects this way Long Buccal Nerve: Infiltration or “Block”

QUESTIONS? PART



WHAT CAN GO WRONG AND WHAT TO DO ABOUT IT?

Infiltration of Mandibular

Molars Buccal and lingual approach

Lingual Infiltration

Advantages: • Thin cortical plate • Lingual foramina • Patient acceptance • Lingual nerve blocked already Lingual Infiltration

Disadvantages: • Ballooning of tissue • Avoiding submandibular salivary gland • Vision Lingual Infiltration

Patient selection criteria enhancement: • Missing adjacent teeth • Thinner alveolar anatomy • Younger/older patients • Root anatomy visible • Vertical buccal shelf form Lingual Infiltration

Technique: • Apical to mucogingval junction • Tissue expands • Avoid submandibular gland • Vision enhanced by position and tongue retraction

Lingual Infiltration - Summary Technique: • Where? Just apical to mucogingival junction • Bevel – facing bone • Depth: 2-3 mm • Volume: 0.5 - 0.7 cc • Onset time: ~ 5 minutes

CONVENTIONAL MANDIBULAR

ANESTHESIA

5 TIPS & TRICKS to think about?

1 Chin up to the ceiling Head position consistent every time! 1

• Consistency • Roll of gravity? 2

Scissors Mouth “Rester” Prop or “rester”

Right side goes with right side technique 3 Volume Considerations • Amount given, then available time for diffusion • Neuroanatomy (penetrable diameter)

How many “carps” are enough… 2 ? are too much … 4 ?

for a block Leonard M, Local Anesthesia Volume and Success Rates, JADA Vol. 126(833) 4 Onset

Time Leonard M, Local Anesthesia Volume and Success Rates, JADA Vol. 126(833)

Lip v. Pulpal Anesthesia 5 The Influence of SOLUTION pH

Primarily due to concentration of HCl the LA molecules are dissolved in. Also proportional to vasoconstrictor concentration and it’s antioxidant, NaHSO3

= H2SO4

The Influence of SOLUTION pH

generic name epinephrine pH 3% mepivacaine ~5.4 4% prilocaine ~5.4 4% articaine 1:200,000 ~4.9 4% prilocaine 1:200,000 ~4.9 2% lidocaine 1:100,000 ~4.3 4% articaine 1:100,000 ~4.3 2% lidocaine 1: 50,000 ~3.9

Cook-Waite / Sterling Research Laboratories

pH of ~ 5.4 favorable “plain” local anesthetic

PART

 ARTICAINE STATUS, REVERSING, BUFFERING, INHALING LOCAL ANESTHESIA AND TOPICALS

LOCAL ANESTHESIA SOLUTIONS

EFFICACY Articaine Articaine Brands: “100” / “200” epinephrine

Septocaine® Orabloc® Articadent® Zorcaine®

Articaine

A statistically significant scientific study demonstrated that 4% articaine 1:100K performed more efficaciously than 2% lidocaine 1:100K in controlled clinical administrations.

Kanaa, MD et al, J.Endod 32:296-298,2006 Articaine

The pulpal anesthetic efficacy of articaine versus lidocaine in dentistry:

Articaine solutions had a probability of achieving anesthetic success superior to lidocaine when analyzing infiltration.

Brandt RC et al JADA 142(5):493-504 2011

Articaine

The pulpal anesthetic efficacy of articaine versus lidocaine in dentistry: • Weaker, but still significant evidence of articaine’s superiority for mandibular block anesthesia. • No difference for symptomatic teeth (e.g. irreversible pulpitis)

Brandt RC et al JADA 142(5):493-504 2011

Chemistry: Sulfur atom

The sulfur atom forming the highly lipid soluble thiophene ring is non-reactive. There is NO cross allergenicity (Ag-Ab) interaction for a patient allergic to “sulfas” or “sodium or potassium metabisulfites”

CH3

H3C NH-CO-CH-NH-CH2-CH2-CH3 Structural formula and physical -

COOCH3  HCI chemical data for articaine

Metabolism – ester component

Although classified as an amide local anesthetic, the articaine molecule is 90% inactivated by plasma cholinesterases and only 10% by hepatic enzymes.

Metabolism

The good news is: 1. The metabolite from the ester linkage inactivation is NOT para-amino benzoic acid (PABA), a known allergen. 2. The FAST action results in a short ½ life (27 minutes). This represents a systemic safety phenomenon.

Search: Safety

These authors could not find a single mortality linked to articaine, in any age group, in it’s years of dental administration in Europe, Canada and currently the U.S.A.

Hawkins JM, Moore PA, Local Anesthesia: Advances in Agents and Techniques, Dent Clin N Am 46 2002 719-73 Search: Adverse Drug Reactions

The product has been available in Germany and France since 1976 and has ~90% of the market, in Canada since 1983 with ~35%, in the United States since 2000, also with ~35%, The authors expected to find ADR reports of post-op sequellae such as lingual nerve and/or inferior alveolar nerve paresthesia. Hawkins JM, Moore PA, Local Anesthesia: Advances in Agents and Techniques, Dent Clin N Am 46 2002 719-732

Search Results: ADR’s

This was NOT the case, implying that: . Not being reported . Not occurring . Accepted as an occasional event in dentistry . Aren’t any lawyers in Europe!

Hawkins JM, Moore PA Paresthesia Research is Unavailable

Is a 4% solution neurotoxic?

There is no scientific or research based data to conclude that 4% prilocaine or 4% articaine is directly causitive of dental paresthesia and/or hypesthesia.

…HOWEVER…

Hawkins JM, Articaine: Truths, Myths and Potentials, Academy of Dental Therapeutics and Stomatology 9 2003

What are YOUR choices?

1. Don’t use it for IAN blocks. Do higher blocks? 2. Use selectively – desperation? 3. Mix, match, dilute(?) with 3% mepivacaine plain (Scandanest®, Carbocaine®) 4. Articaine for IAN/Lingual - with consent? 5. Patient selection? NOTE: Speaker suggests: Do NOT use on lawyers, news anchor women, any media, family, alleged friends or at 4:00 PM Thursday or Friday afternoons Dr. George Gow-Gates, Dr. J. Watson, University of Sydney, Australia QUESTIONS?

OraVerse™ Phentolamine Mesylate Injection

“Reversing” Local Anesthesia Phentolamine Mesylate reverses SOFT TISSUE ANESTHESIA ONLY

Phentolamine Mesylate is NOT a LOCAL ANESTHETIC reversal agent

13% of pediatric patients receiving IANB suffer post-treatment traumatic injury to soft tissues.

College C, Feigal R, Wandera A, Strange M. Bilateral versus unilateral mandibular block anesthesia in a pediatric population. Pediatr Dent. 22(6):453-457, 2000. Adults and Adolescents: 60 Minute Efficacy Data Time to Recovery of Normal Lip Sensation

Mandible • 54.8%; p<0.000 Phentolamine mesylate accelerates the return to normal sensation by 85 minutes • 41% phentolamine mesylate patients fully recovered in 60 minutes • 7% for control patients

0171, Rev. 10/2008 Pediatric patients also recover sensation in half the time

• Median time to recovery of normal Patients 6-11 years old lip sensation compared to control was reduced by: – 120 minutes (67%) in the mandible – 53 minutes (47%) in the maxilla Source: Tavares M, Goodson JM, Studen-Pavlovich D, and colleagues. Reversal of soft-tissue local anesthesia with phentolamine mesylate in pediatric patients. JADA 2008;139(8):1095-1104. Copyright ©2008 American Dental Association. All rights reserved. Excerpted0360, Rev. 11/2010 by permission. Dosing

• Easy to Dose − 1:1 cartridge ratio to local anesthetic with a vasoconstrictor using identical injection site • Maximum recommended dose − 2 cartridges for adults & adolescents 12 years of age and older − 1 cartridge for patients 6-11 years of age and over 66 lbs. − ½ cartridge for children 6 years of age or older weighing 33-66 lbs.

Potential complications

Needle-related: • Trismus • Paresthesia OraVerse TM

Now sold in sleeves of ten (10)

Phentolamine Mesylate OraVerse™ Cost?

$8/cartridge

Onset® Buffering Local Anesthetic

Orapharma Anutra Performance Limitations of Current Anesthetics

•Onset Time Time for body to buffer anesthetic •Analgesia Is No pain attainable? Always? •Injection Pain Stinging is a concern for patients

Clinical Study Data Pulpal - IANB

Percentage of Participants Profoundly Numb at 2 Minutes

80%

71% of the participants 70% 71% receiving buffered 60%

anesthetic achieved 50%

pulpal anesthesia in 40%

under two minutes 30%

20% 12% of the control participants achieved pulpal 10% 12%

0% anesthesia in under two minutes Control Onset Clinical Data – Pain Free Injections

Zero Injection Pain of buffered anesthetic 50% 44% 45%

patients experienced 40% 44% zero injection pain 35%

30%

25%

20% 6% of traditional anesthetic 15% patients experienced 10% 5% zero injection pain 6% 0% Control Onset®

From: Malamed S, Falkel M, Decreasing anesthetic injection pain using an automated dental anesthetic buffering system: A prospective, randomized, double- blind, crossover study, Draft for Publication, 2011 Clinical Data – Patient Preference

Which was the most comfortable injection? 80%

70% 72% 72 % of patients 60% rated Onset as 50% 40%

the most 30%

comfortable 20%

10% 17% injection 11% 0% No Difference Control Onset®

 Onset + Lidocaine Lidocaine 67 %

Articaine

Onset® by Onpharma® The exchange volume is only 0.18 ml.

The first and only chair side approach for precision buffering of local anesthetic

Cartridge Connector Bicarbonate Solution Mixing Pen

$299.00 $55.00 / day based on X9 use Not autoclavable Topical

Anesthetics

Product Analysis Topical Anesthetic: Compromises

Apply and Saliva Isolate Reapply ejector

1 2 3 4 5 6

Dry Be patient Don’t = 90 sec.  talk! Topical Anesthetics

• What do you do if you KNOW that the area can’t be isolated (saliva, tongue), or • The topical won’t penetrate into tissue far enough to cover a deeper block? Topical Anesthetics

Patients expect the use of a topical anesthetic!

Dr. Kit Weathers Endo Magic® Founder’s Technique! Griffin, GA. Lidocaine Viscous

FDA announces Box Warning Required Product Analysis: Lidocaine HCl “Should not be used for teething pain” Product Analysis: E.M.L.A.

Eutectic Mixture of Local Anesthetic: 2.5% lidocaine + 2.5% prilocaine Product Analysis: Oraqix Local Anesthetic News:

Pregnancy 5 Cover Story: ® JADA AUGUST 2015 JADA 146(8) THE JOURNAL of the AMERICAN DENTAL ASSOCIATION

Dental Treatment Safety with Local Anesthetics during Pregnancy 572

Hagai, A, Diav-Citrin , O, Shechtman, S, Ornoy, A, JADA 146(8) Aug 2015

Pregnancy: Safety- Local Anesthetics

A prospective, comparative observational study by the Israeli Teratology Information Services (TIS) – 1999 – 2005 n = 210 pregnancies exposed to dental local anesthetics (112 [53%] in 1st trimester) vs. control group = 794 pregnancies not exposed to teratogens

Hagai, A, Diav-Citrin, O, Shechtman, S, Ornoy, A, JADA 146(8) Aug 2015 Pregnancy: Safety- Local Anesthetics The rate of major anomalies was not significant between the groups.

There was no difference in the rate of miscarriages, gestational age at delivery or birth weight. Hagai, A, Diav-Citrin, O, Shechtman, S, Ornoy, A, JADA 146(8) Aug 2015 Pregnancy: Safety- Local Anesthetics

The most common type of dental treatment was endodontic therapy initiation (43%) and exodontia (31%). Most women were not exposed to additional medications. ~ one-half (51%) were not exposed to dental radiography. 44% were exposed to radiation, mostly bite wings.